16cos(x)-3sec(x)=0

Question

Find all solutions for x in [0, 2pi)

Answer 1

16cos(x)-3sec(x)=0
16cos(x) = 3sec(x)
16cosx = 3/cosx
cos^2 x = 3/16
cosx = ± √3/4
x = 1.123
or
x = π - 1.123 = 2.0186
or
x = P + 1.123 = 4.266
or
x = 2π - 1.123 = 5.160